The noisy environment in our industrial society is a health hazard to numerous workers as well as to people engaged in recreational activities generating loud noises, or simply listening to music with varying volume settings from individual digital music players such as an Ipod™, MP3 players or the like, via a set of earphones or the like.
Many documents such as U.S. Pat. No. 3,789,952 granted to Widegren et al., U.S. Pat. No. 7,151,835 granted to Yonovitz et al., US patent publication No. 2009/0208024 A1 to Farver and European patent No. EP 1,816,892 B2 to Ruwisch aim at limiting the harm produced by the continuous estimated noise/sound reaching the user's ear which could induce permanent partial hearing loss. These methods and devices typically integrate by estimation the total noise dose received by the user's ear, considering a sound generation via the speaker inside the headset of the user, as well as the estimated added noise contribution of the user surroundings or environmental noise as measured by and external microphone located on the headset. Upon the calculated total dose reaching a pre-determined threshold, an action or protective measure is taken by the processor.
These integrated total doses are estimated depending on the type of earpiece or headset being worn by the users, and considering their partial occlusion of the ear canals, the estimated cumulative total doses are only estimations and not real measures of the ear exposures. These estimations do not take into account the actual positioning of the earpieces inside the user's ears, which may vary considerably from one user to another, as opposed to constant and known occlusion occurring when using custom-fitted in-ear devices, as disclosed in U.S. Pat. No. 6,754,357 granted to McIntosh et al., U.S. Pat. No. 6,687,377 granted to Voix et al., and U.S. Pat. No. 7,688,983 granted to Voix et al. Furthermore, these estimated integrations do not take into consideration the fact that the human ear rests, or recuperates from auditory fatigue over time, especially when the sound pressure level or the ambient noise is relatively low.
With the always increasing popularity of personal music players (PMP) or the like, users tend to constantly wear the headphones to listen music or the like. In such cases, the users essentially become acoustically disconnected, at least partially, from surrounding ambient sounds and/or noises, which could cause dangerous situations. In order to be in hearing contact with the environment, the users need to either significantly reduce the sound or playback volume of the PMP or remove at least one of the two headphones, which might become annoying, especially if that kind of situation occurs frequently.
Many documents such as U.S. Pat. No. 3,819,860 granted to Miller, U.S. Pat. No. 6,754,359 granted to Svean et al., and U.S. Pat. No. 7,502,484 granted to Ngia et al. teach an ear terminal with an internal microphone for clean voice pickup from the user. This measured voice signal, although clean (essentially noiseless), is not a natural speech voice since the higher frequencies have essentially been transformed, by the surrounding body parts, into lower frequencies, giving the impression of an occlusion effect in that the voice is muffled or captured from inside a box, or closed cavity or the like, such that it is not preferred for transmission via a telecommunication network or the like.
Accordingly, there is a need for an improved earpiece device and method.